Hi there,
Since you are legally divorced, it will be better if you should take the help of a legal expert.I’m sure even court lets the father to interact with the child with some term and conditions.
We are all human beings and human emotions change with time, experiences and maturity.
Next Steps
So take the help from a legal expert and a mental health professional ( may be a child psychologist if possible).
Do involve your family members and friends in such issues.